Low ground pressure and amphibious coring system

ABSTRACT

An amphibious coring apparatus is provided for operations on ground including wetlands. A rig deck is supported above a substructure. The substructure has mobile, low ground pressure, wetland-engaging ground components. Between the deck and the substructure is an articulation interface for leveling the rig deck. A top drive is movable in a derrick for rotating a drill string. Hydraulic rams supported from the deck raise and lower the top drive, such as by a cable extending over a sheave at a top end of each ram. A pipe handler racks pipe to and from multiple tiers and a live bottom trough assists with tripping pipe.

CROSS-REFERENCE TO RELATED INVENTION

This application is a regular application of U.S. provisional patentapplication Ser. No. 60/940,443, filed May 28, 2007, the entirety ofwhich is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to apparatus and methodology for obtainingsubterranean core samples, more particularly for drilling apparatuswhich exert low ground pressure and having synergistic adaptationsrelated thereto.

BACKGROUND OF THE INVENTION

Sensitive environments including wet terrain, such as muskeg and swampyareas, are an impediment to drilling and coring operations as thefragile environment is easily damaged.

Accordingly, many such operations have been restricted to the winterseason when conventional equipment can be supported on frozen ground.The usable window for a winter season in Alberta, Canada can be as smallas three months before a thawing break-up approaching the spring season.

SUMMARY OF THE INVENTION

Embodiments of the invention relate to low ground pressure or toamphibious capable equipment for accessing sensitive environments yeararound, including after the winter thaw. The apparatus of the inventionimposes less than one-half the pressure of the human foot and use ofenvironmentally friendly hydraulic fluids, in a substantiallyall-hydraulic rig, minimize risk.

Embodiments of the invention relate to equipment which can betransported to the sensitive areas on conventional transports and withinrestrictions including weight and size. Accordingly, components of theequipment which are oversize when erected for operation, can becollapsed or pivoted to a low profile, such as for hauling on a low-boytrailer.

Embodiments of the invention further relate to equipment which can adaptto uneven terrain, without extraneous leveling jacks or blocking. Thelow-ground profile or amphibious equipment includes an articulatedplatform which can be leveled relative to the equipment's mobile base.

In one broad aspect of the invention, an amphibious coring apparatus isprovided for operations on ground including wetlands comprising: a rigdeck; a substructure supporting mobile, low ground pressure,wetland-engaging ground components; and an articulation interfacebetween the rig deck and substructure for leveling the rig deck. Thearticulation interface can be stabilized with lateral and longitudinalbars.

The apparatus of the current invention enables drilling over wetlands inall seasons. In a broad aspect a method is provided for drilling inwetlands comprising: moving an amphibious, low ground pressure coringapparatus onto the wetlands supported on wetland-engaging groundcomponents, and articulating a rig deck relative to the groundcomponents for orienting a derrick for drilling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of the invention on siteand illustrating a transportable drilling/coring apparatus placedadjacent a transportable mud unit;

FIG. 2 is a perspective view of an embodiment of the transportabledrilling/coring apparatus with the plating of the deck removed forviewing the structures therebelow;

FIG. 3 is a top view of an embodiment of the rig with the derrickerected;

FIG. 4 is a bottom view of the rig of FIG. 3;

FIG. 5A is a front elevation of the derrick illustrating the top driveat the rig deck;

FIG. 5B is a perspective view of the derrick of FIG. 5A;

FIG. 5CB is a close up perspective view of the rams and sheaves of thederrick of FIG. 5A;

FIG. 6 is an elevation view of an embodiment of the transportabledrilling/coring rig;

FIG. 7 is a front elevation view of the rig of FIG. 6;

FIG. 8 is a front, underside and perspective view of a deck, thearticulation interface and the substructure having the pontoons removedfor improved viewing of the interface

FIG. 9 is a rear perspective view of a deck, the articulation interfaceand the substructure having the pontoons removed for improved viewing ofthe interface;

FIG. 10 is a perspective view of one embodiment of the pipe handlershowing a rack only on one side;

FIG. 11 is an end view of the pipe handler of FIG. 9 illustrating rackson either side of the pipe handler;

FIG. 12 is a perspective view of the mud unit and deck with the pontoonsand tracks removed;

FIG. 13 is a left side view of the mud unit of FIG. 12 illustrating thearticulation interface between the deck and the substructure;

FIG. 14 is a front view of the transportable frame of FIG. 13,

FIG. 15 is a perspective view of auxiliary transportable unit; and

FIG. 16 is a rear view of the auxiliary transportable unit of FIG. 15.

DESCRIPTION OF EMBODIMENT OF THE INVENTION

In greater detail and with reference to FIG. 1, embodiments of anapparatus for coring or drilling comprise a rig 10 that can work inwetlands year around. Typically the rig 10 is associated with otherequipment such as at least a mud unit 100.

The rig 10 is amphibious (including land, water, muskeg, big andcombinations thereof), comprising: a rig deck 11 and a substructure 12which supports ground-engaging, motive, ground components M like wheelsor tracks. The ground components M impose a low ground pressure on thesupporting wetland. In one embodiment, the ground components M of thesubstructure 12 can comprise pontoons 13 fit with tracks 14 so that therig 10 is both mobile over soft ground and can be amphibious. The tracks14 can be driven with systems similar to skid-steer equipment. Suitablepontoons, tracks and drive systems can be sourced from Wetland EquipmentCompany, Inc., Louisiana, USA.

As shown in the embodiment of FIGS. 2-4, a rig deck-mounted dieselengine 19 provides hydraulic power for driving the tracks 14. The tracks14 can be driven by one or more drives comprising hydraulic motors 21and a drivetrain (such as gearboxes 22, chain and sprocket arrangements23) which can be fit to the substructure 12 for driving the tracks 14.The diesel engine 19 also provides hydraulics generally for the rig 10overall.

Drilling and coring operations utilize pipe 30 which, for mostoperations, can be racked on the rig deck 11. Best seen in FIGS. 1, 8and 9, a pipe racking system 32 enables pipe 30 to be loaded andunloaded at horizontal racks 33 supported on the rig deck 11. The rig 10includes a driver's cab 34 and a doghouse 35 housing coring/drillingcontrols.

With reference to FIGS. 5A-5C, a hydraulic top drive 42 is guided in adolly 43 up and down the derrick 40 for rotating pipe 30. Conventionalequipment is provided, such as hydraulic lines and mud hoses 44 are notdetailed. Further, other conventional equipment includes pipe handlingsuch as iron roughneck and power tongs, hydraulic bails and elevators,power slips and automated tripping.

With reference also to FIG. 2, the top drive 42 is actuated up and downthe derrick 40 using one or more actuators, such as a pair of hydraulicrams 45. Each ram 45 comprises a cylinder 46 secured to the deck 11 at alower end and stabilized laterally in the derrick at an upper end, atabout one half the height of the derrick. Each ram 45 further comprisesa rod 47 for extension from each cylinder 46 and operable from about onehalf the height of the derrick to the top 48 of the derrick. Full rangeof motion of the top drive 42 from rig deck 11 to the top 48 of thederrick is accomplished with a cable (not shown), one end of which isfixed such as to the deck 11, extends over a sheave 49 fit to each rod47, and the other end being secured to the top drive dolly 43. When therod is fully retracted to the cylinder 46, the top drive is at the deck11. As the rod 47 is extended, the cable passes over the sheave,doubling the displacement of the top drive 42 relative to the rod 47.The top drive travels twice the lineal travel of the rod. Accordingly,extension of rod of ½ of the derrick, moves the top drive 42 from thedeck 11 to the top 48 of the derrick. Lifting loads from the top drive42 are directed to the rig deck 11 through the rams 45 and avoidimposing vertical loads on the derrick 40, eliminating crown loads andenabling a lightweight derrick design. The derrick 40 is fit with ahinge 44 (FIG. 1) adjacent a deck end for pivoting from an upright,substantially vertical, operational position to a substantiallyhorizontal and low shipping or transport position. Depending on the formof transport, the entire rig 10 including derrick 40 can be transportedbetween sites at or below road height restrictions for road transport.

With reference to FIGS. 6 and 7, typically a drilling derrick 40 isoriented vertically or otherwise oriented for particular operations. Thederrick 40 is supported by the rig deck 11, the rig deck is supported onthe substructure 12 and the substructure is supported by thesubstructure's ground components M. Due to uncertain wetland conditions,the orientation of the substructure 12 is less likely to be optimal forthe derrick orientation. Accordingly, an articulation interface 15 isemployed between the rig deck 11 and substructure 12 for orienting therig deck 11, typically oriented to the horizontal for orienting thederrick 40 vertically thereon. Accordingly, articulation interface, orleveling system, operative between the deck and the ground components Menables the unit to be operated on zero-ground disturbance locationsincluding off-level footing.

As shown in FIGS. 6-9, the deck 11, whether it is for the rig 10 or mudunit 100, is articulated upon the articulation interface 15, andactuable to level the deck 11, regardless of an uneven orientation ofthe substructure and ground components (pontoons 13 and tracks 14shown). Typically, the deck 11 is supported above the substructure 12upon a three or a four point connection. As shown in FIGS. 6 and 7, thedeck 11 can be pivoted on a three-point articulation interface 15, twopoints forward and one point rearward wherein one forward point and onerearward point are elevation adjustable. At least two jacks arerequired; one for side-to-side and one for front-to-back adjustment.Three jacks 50 are illustrated for connection to front pivots 51 andrear pivot 52. Two front jacks 50 f, 50 f are located at two laterallyspaced front pivots 51 d, 51 d and 51 s, 51 s, at each of the deck 11and substructure 12 respectively, towards the front of the rig 10. Onesubstantial rear jack 50 r and rear pivot 52 d, 52 s, at each of thedeck 11 and substructure 12 respectively, is located towards the rear ofthe deck 11. The front pivots 51,51 are spaced forward of the rear pivot52. The two front jacks 50 f, 50 f actuate at least side to sideleveling and can participate in some front to rear adjustment. The rearjack 50 r and the one or more front jacks 50 f, 50 f can actuatefront-to-back leveling. The rear and front pivots 51,52 are distributedunder the deck 11 for load distribution to the substructure 12.

A four point articulation interface comprises four points of connection,two points forward and two points rearward, and at least forward pointand one rearward point being elevation adjustable.

With reference to FIGS. 8 and 9, a pair of lateral stabilizing bars 54are provided, one forward and one rearward, extending between the deck11 and the substructure 12, to ensure the deck 11 stays aligned andstabilized side-to-side over the substructure 12. Similarly, at leastone longitudinal bar 55 is provided to ensure the deck 11 stays alignedfront-to-back over the substructure 12. The bars are articulated at eachconnection, one end to the deck and another end at the substructure. Thebars are provided in embodiments in which the jacks 50 are highlyarticulated and additional stabilization is desired.

In embodiments having a pair of parallel, spaced tracked pontoons 13,the pivots 51,52 and jacks 50 f, 50 f, 50 r are fit between the trackedpontoons 13. The jacks 50 can be articulated actuators such as hydraulicrams.

With reference to FIGS. 10 and 11, an embodiment of the pipe rackingsystem 32 includes a pipe rack 33, which can include a pipe handler 60and one or more tiers 63 for storing pipe 30, and multi-tiers 63 (fivetiers illustrated in FIG. 2, with multi-tiers obscured by pipe 30). Oneexemplary, lowermost, tier 63 is shown in FIG. 10. The pipe handler 60can be automated for loading and unloading pipe 30 from each tier 63.The pipe handler 60 is actuated to both elevate, to access tiers 63, andtip for loading and unloading pipe 30 to and from the selected tier ofthe racks 63. The pipe handler comprises a trough 67 and a conveyor 66positioned under the trough 67 for directing pipe 30 therealong.

A conveyor 66 and pipe trough 67 is supported on height adjustabletrough supports 68 (one shown). Each trough support 68 is adjustable toposition the trough 67 at each tier 60. Best seen in FIG. 11, eachsupport 68 can be a tubular support 69 movably and axially actuablethrough a sleeve 70. The trough supports 68 can be actuated using one ormore hydraulic rams. The trough 67 is pivotable left and right forreceiving and unloading pipe 30. The trough 67 has a live bottom troughfor assisting with tripping pipe 30. When a pipe 30 is lowered by thetop drive 42, the conveyor 66 is actuated to direct a pipe end away fromthe derrick 40 and to lie the pipe 30 down in the pipe handler trough 67for subsequent tipping and racking in a tier 63.

With reference to FIGS. 12 and 15 respectively, the rig 10 of FIG. 1 istypically accompanied by the mud unit 100 (FIG. 12) for drillingoperations and can further include an auxiliary unit 200 (FIG. 15).Similarly, the mud unit 100, and even the auxiliary unit 200, can alsobe articulated for leveling purposes.

With reference to FIGS. 12-14, an embodiment of the mud unit 100 alsocomprises a working deck 11 for support on a substructure 12 (typicallyinterchangeable with the substructure of the rig 10. The working deck 11typically supports a mud pump, mud tank, mix hopper, shaker, degasserand auxiliary equipment including hydraulic power pack and aircompressor. As shown in FIG. 14, an articulation interface 15 can besimilarly provided as described for the rig 10 including rear pivot 52and front pivots 51,51.

Suitable equipment and capacities possible include 1.7M³ Gardner Denverpump at 1000 psi, Mission 5 by 6 centrifugal pumps for precharge, mixingand mud roll, a Derrick 313M shaker, and a 20 m³ tank according toAlberta Energy Utility Board (EUB) regulations. Sensors monitor tanklevel, pumps and alarms.

The substructure can be convertible so that the pontoons and tracks canbe swapped out for a substructure supporting large footprint tires andsuitable drives (not shown).

As shown in FIG. 11, an embodiment of the rig 10 and mud unit 100 aresetup on location for conducting operations. The units are ideal forshallow core drilling in the order of 300 m and support services andscaled-up rigs are contemplated to core drill to depths of 700 m.

The rig 10 has a low ground impact and is suitable for environmentallysensitive areas. Applicant believes that the rig footprint is about ½ ofthe footprint of other similar coring rigs. One embodiment of the rig is38 feet by 44 feet. Accordingly, the rig has a small location sizerequirement and can fit on smaller resource leases while still meetingother drilling regulations. Despite units weighing in the order of110,000 pounds, the ground pressure is about 2 to 4 psi and will notcompact muskeg. Further, using other arrangements of rig 10 and mudunits 100, such as those being arranged end to end, coring can beperformed off lease, on access roadways or on lease roads. As shown,with a derrick 40 fit with a pair of 6″ rams 45, the rig can implement aRange II derrick capable performance of 50,000 pound pull and a 20,000pound push and typical coring depths of 300 m or so for oil sandsdeposits in Northern Alberta, Canada. Other capacities including RangeIII are contemplated. Auxiliary capability includes 12,000 pound workingwinch and a 3,500 core winch.

Having reference to FIGS. 13 and 14, an embodiment of an auxiliary unit200 comprises an amphibious drive base with a deck 11 having water andvacuum capability with a picker for a variety of lifting duties. Onesuch auxiliary unit can transport pipe, cores and equipment and store 15m³ of water and a 15 m³ vacuum tank 201.

A suitable vacuum tank 201 is a Rebel 15 m³ tank meeting TC-412 tankspecifications and fit with a Hibon VTB820 blower. The water tank can befit with a Bowie pump. Further, the auxiliary unit can be fit with asteam system for cleaning duties such as rig-cleaning. A suitable craneor picker 202 could include a Hiab 166B-3CL Knuckle-boom picker.

The rig 10, mud unit 100 and auxiliary unit 200 can be transported byroad on low-boy trailers and then self-powered on their drive bases tothe coring/drilling location, including amphibious and muskeg locations.It is also contemplated that the decks of the units are separable fromthe drive bases for separate shipping by truck and trailers.

1. Amphibious coring apparatus for operations on ground includingwetlands comprising: a rig deck; a substructure supporting mobile, lowground pressure, wetland-engaging ground components; and an articulationinterface between the rig deck and substructure for leveling the rigdeck.
 2. The apparatus of claim 1 wherein the ground components comprisetracked pontoons for low ground pressure support on the ground.
 3. Theapparatus of claim 1 wherein the articulation interface comprises threeor more spaced points of connection, two of which are elevationadjustable for adjusting the fore-to-aft and side-to-side angles of therig deck relative to the substructure.
 4. The apparatus of claim 1wherein the articulation interface comprises three points of connection,two points forward and one point rearward wherein one forward point andone rearward point are elevation adjustable.
 5. The apparatus of claim 1further comprising stabilizing bars extending between the deck and thesubstructure for lateral and longitudinal stabilization.
 6. Theapparatus of claim 1 comprising front and rear stabilizing barsextending laterally between the deck and the substructure forside-to-side stabilization and at least one longitudinal stabilizing barextending longitudinally between the deck and the substructure forfront-to-rear stabilization.
 7. The apparatus of claim 1 wherein thearticulation interface comprises four points of connection, two pointsforward and two points rearward and at least forward point and onerearward point being elevation adjustable.
 8. The apparatus of claim 1wherein the substructure further comprises two tracked pontoons forsupporting the apparatus with 2 to 4 psi ground pressure.
 9. Theapparatus of claim 8 wherein the substructure further comprises one ormore drives for powering the tracked pontoons.
 10. The apparatus ofclaim 9 wherein the one or more drives are powered from the rig deck.11. The apparatus of claim 1 further comprising a pipe rack supported onthe rig deck.
 12. The apparatus of claim 11 wherein the pipe rackfurther comprises an automated pipe handler for loading and unloadingpipe.
 13. The apparatus of claim 12 wherein the pipe rack furthercomprises: one or more tiers for storing pipe, and wherein the automatedpipe handler loads and unloads pipe from each tier.
 14. The apparatus ofclaim 13 wherein the pipe rack further comprises: a trough; and aconveyor positioned under the trough for directing pipe therealong. 15.The apparatus of claim 14 wherein the trough and conveyor are heightadjustable for loading and unloading pipe at each tier.
 16. Theapparatus of claim 1 further comprising: a derrick, wherein the derrickfurther comprises a top drive, and one or more actuators for moving thetop drive along the derrick.
 17. The apparatus of claim 16 wherein theone or more actuators are hydraulic rams mounted between the deck andthe top drive.
 18. The apparatus of claim 16 wherein the one or moreactuators are hydraulic rams comprise: a cylinder supported by the deck;a rod fit with a sheave; and a cable extending over the sheave to thetop drive, wherein the top drive travels twice the lineal travel of therod.
 19. The apparatus of claim 16 wherein the derrick is pivotallymounted to the rig deck between a substantially horizontal transport anda substantially vertical operational position.
 20. A method of drillingin wetlands comprising: moving an amphibious coring apparatus having arig deck onto the wetlands, the apparatus having low ground pressure,wetland-engaging ground components; and articulating the rig deckrelative to the ground components for orienting a rig deck supportedderrick for drilling.